听力原文：A new study by American Institutes for Research found that more than a half of 4-

year college students and nearly 75% of 2-year college students lack the ability to figure out a tip, compare prices or even balance a checkbook. There's been an assumption out there that college students are graduating with ascertained level of what we do expect proficient skills. In this study really shows that some of those assumptions may not be correct. But the problem researchers say is the majority of them can't comprehend when they just read.Some students say they are not surprised by the results and colleges need to do more to better prepare them. It's irresponsible and negation for colleges just be able to put their name in the university of people's degrees and send the people to workforce when they're unprepared and unskilled.

How many 2-year college students do not have the ability to figure out a tip？

A．50%

B．75%

C．70%

D．85%